SHARKS

488 Sharks
Carcharhinus porosus (Ranzani, 1840) CCR
Frequent synonyms / misidentifications: None / Rhizoprionodon terraenovae (Richardson, 1836),
Rhizoprionodon porosus (Poey, 1861), Rhizoprionodon lalandii (Müller and Henle, 1839).
FAO names: En -Smalltail shark; Fr - Requin tiqueue; Sp - Tiburón poroso.
ventral view of head
upper and lower
tooth near centre
Diagnostic characters: Body slender and fusiform. Eyes large, internal nictitating lower eyelids present.
Snout long, preoral length 1.2 to 1.8 times internarial width, and narrowly rounded to pointed; nostrils
with a pointed, narrow-based anterior nasal flap; upper labial folds short. Teeth with serrated edges,
those in upper jaw with narrow cusps, becoming progressively oblique towards the sides, those in
lower jaw with high narrow cusps, erect in front, oblique posteriorly; anteroposterior tooth row counts on
each side 13 to 15/12 to 15, total tooth row counts 29 to 32/26 to 32. Spiracles absent; gill slits relatively short,
height of third gill slit about 2.8 to 3.4% of total length; gill arches without papillae. First dorsal fin moderately
low, height 6.9 to 9.9% of total length; first dorsal fin with a broadly convex anterior margin, a narrowly rounded
apex, an origin over pectoral fin inner margins, and the midlength of its base much closer to the pectoral-fin insertions
than the pelvic-fin origins;second dorsal fin high although much smaller than first dorsal fin, height 2.2
to 2.8% of total length; second dorsal fin with a nearly straight or shallowly concave posterior margin, an origin
over or slightly behind midpoint of anal-fin base, a somewhat elongated free rear tip, and an inner margin
much less than twice the fin height; anal fin with a deeply notched posterior margin and without long
preanal ridges; pectoral fins short, slightly falcate, and with narrowly rounded apices. Interdorsal ridge absent
between dorsal fins; no keels on caudal peduncle. Precaudal vertebral centra 41 to 61, total vertebral
centra 96 to 135. Colour: back greyish blue or leaden, belly paler; sides and pelvic fins tinged with reddish in
some individuals.
Size: Maximum total length to 134 cm; common to 90 cm; size at birth between 31 and 40 cm; males maturing
between 72 and 78 cm, females at 84 cm or below.
Habitat, biology, and fisheries: Coastal, common in shallow waters (16 to 32 m) over muddy bottoms, especially
in estuaries. Number of young 2 to 7 per litter. Feeds on bony fishes, other small sharks, and small invertebrates,
mainly crabs and shrimp. Caught throughout its range. Separate statistics are not reported. Caught
mainly with gill nets and longlines. Important
catches occur off Trinidad in the area and off
northern Brazil. Marketed fresh-frozen and
salted for human consumption, also for liver oil
and fish meal. Conservation status uncertain.
Distribution: Western Atlantic from the Gulf of
Mexico to southern Brazil; also along the Pacific
coast of the Americas from Mexico (Baja, California)
to Peru.Recorded from Gulf of Mexico (USA,
Mexico), Trinidad and Tobago, and Panama, Suriname,
and Venezuela, apparently absent from
the Bahamas and the Greater and Lesser Antilles;
also northern and southern Brazil.